Yamaha EMX3500 Owner's Manual - Page 13

OPERATING TIPS Cautions for Connected Sources Please observe the following cautions when connecting sound sources to the EMX3500: • TURN THE POWER OFF FIRST Always make sure that the mixer's POWER switch is turned off before connecting or disconnecting any cables. Failure to do so can damage the EMX3500 or connected equipment. • TURN THE MIXER ON LAST Always turn the mixer's POWER switch on after first turning on connected sound sources such as electronic instruments or audio equipment. • DO NOT CONNECT AMPLIFIED INPUT Never connect the speaker-level output of any amplifier to the mixer's inputs unless you use a suitable highlevel attenuation pad or "direct box" to lower the signal's level. Matching Input Levels When matching input levels, it is a good idea to first make sure that the speaker systems are disconnected from the mixer's speaker outputs. (This must be done with the mixer's POWER switch turned off.) The sound can be monitored using a pair of headphones plugged into the front-panel PHONES jack-but make sure that the master stereo faders are set to their minimum levels at first, then raise them just enough to produce a comfortable sound level when you actually begin monitoring input signals and matching levels. Once all your sources are connected and the entire system is turned on, it is important to accurately match the input sensitivity of each input channel with the source signal it will receive. Do this one channel at a time. Begin by setting the lowest possible sensitivity for the input: turn the PAD switch on, set the GAIN control to -16, and slide the channel fader to between "10" and "5" on its scale. Now apply a signal to the input. Play the connected source instrument at the loudest level it will produce in actual use-or if the source is a microphone, have the vocalist sing his or her loudest note into it-and watch the channel's PEAK indicator carefully. If it lights at this point, the output level of the source must be reduced. Normally, however, you will have to increase the input sensitivity to achieve optimum matching. Gradually increase the setting of the GAIN control until the PEAK indicator just barely flashes on the loudest peaks. If you turn the GAIN control up all the way and the PEAK indicator still does not light, then reduce the GAIN control setting to minimum, turn the PAD switch off, and gradually increase the GAIN setting again. This time the PEAK indicator should light somewhere in the GAIN control range. If it does not, check that the source is functioning properly and that it is properly connected to the appropriate input of the mixer. You may also want to check the connecting cable for faults. Since the PEAK indicator lights when the channel signal is 3 dB below the clipping level, it is okay if it flashes briefly on loud peaks. In fact, this is about the optimum input sensitivity setting. When you've matched the first channel, set its fader to minimum and begin matching the next channel. Repeat this procedure for each channel you will use in the mix. Once the input level of each channel has been matched, set the master stereo faders to their minimum positions and turn the POWER switch off. Reconnect the speaker systems, then turn the power back on. The master faders can now be gradually raised to their operating levels. Setting Channel and Master Faders The final positions of the channel faders will naturally depend on the overall mix you set up. However, there are two important points you should keep in mind when setting channel levels. The channel faders have an optimum range that provides the maximum control margin with minimum noise and distortion. The optimum range for the channel faders on the EMX3500 is between about "5" and "15" on their scales. There is no rule that says you must avoid higher or lower settings, but remember that the best sound quality can be achieved within this range. Settings in this range also provide sufficient leeway for later adjustments. Remember, too, that changing the setting of any single input channel fader will affect the overall output level. This is why it is important to watch the VU meters when setting the input channel and master stereo faders. These meters 11